when slicing from command line an object with 3 volumes/shells, the print center is displaced

[lucaskmiyazaki]

Describe the bug when slicing from command line an object with 3 volumes, the print center is displaced. The object I am printing are 3 aligned cylinders stacked together. But I also tested 3 stacked cubes and the same outcome happened. The file I am using has the following structure:

<?xml version="1.0" encoding="UTF-8"?>
<amf unit="millimeter">
  <metadata type="cad">TissueWeb</metadata>
  <object id="0">
    <metadata type="slic3r.extruder">0</metadata>
    <metadata type="name">Composition</metadata>
    <mesh>
      <vertices>
         ...
      </vertices>
      <volume>
        <metadata type="slic3r.extruder">1</metadata>
        <metadata type="name">cylinder.stl</metadata>
        ...
      </volume>
      <volume>
        <metadata type="slic3r.extruder">2</metadata>
        <metadata type="name">cylinder.stl</metadata>
        ...
      </volume>
      <volume>
        <metadata type="slic3r.extruder">3</metadata>
        <metadata type="name">cylinder.stl</metadata>
        ...
      </volume>
    </mesh>
  </object>
</amf>

When I convert this .amf file using the command:

slic3r --print-center 67.5,53.5 data/temp/1650309937326.amf -o data/temp/1650312790779.gcode

the output gcode has its center on a completely different location. but when I remove the 3rd volume from the file and use the same command, slic3r successfully prints the object on the center.

To Reproduce Steps to reproduce the behavior:

1. Go to Ubuntu Terminal
2. Install slic3r v1.3.0
3. Generate a .amf file with 3 volumes
4. Type command slic3r --print-center 67.5,53.5 data/temp/1650309937326.amf -o data/temp/1650312790779.gcode

3D Model and Slic3r Configuration Export temp.zip

Desktop:

• OS: Ubuntu v21.04
• Slic3r Version 1.3.0